Wot, no Banksy? There was some gossip before the announcement of this year's Turner prize shortlist that the street artist who comically portrayed his own cultural milieu this year in his film Exit Through the Gift Shop might make the grade. Given that, according to Tate Britain's director Penelope Curtis, no artist turned the nomination down, perhaps the judges never seriously considered him. But they should have done: the cult of Banksy may be annoying, but he has added new dimensions to his work this year that prove him a worthwhile and clever artist who would have added a lot of excitement to this year's Turner prize. Frankly, it needs some.

Superficially, this year's shortlist might seem to resemble last year's (declaration of interest: I was on the 2009 jury). It has a similarly eclectic balance, and recognises quieter, serious artists. The painterly installations of Angela de la Cruz, which play on tensions between three-dimensional sculpture and the pleasures of pigment, might make her this year's equivalent to the inspiring 2009 winner, muralist Richard Wright. And, like Wright, the sound artist Susan Philipsz is a product of the outstanding Scottish art scene; she creates installations that place songs from various sources into public spaces ranging from a seafront shelter to a bridge on the Clyde.

The Otolith Group make pretentious, academic film art laden with references to everything from Tarkovsky to Derrida. Fans of their work might see it as a kind of multicultural Godart, but to say that is simply to evoke its indigestible aridity. But the real low-point for me is the final artist here, Dexter Dalwood, whose work might make him a candidate for the world's first talent transplant. Dalwood was tried, tested and rejected when New Labour was still cool, as a leader of Charles Saatchi's now-forgotten "new neurotic realist" movement in the late 1990s. His glib, ordinary canvases are not in the same league as paintings being done today by young artists in Germany or old artists in Britain – and, as a lover of painting, I would rather they had not shortlisted a painter at all.

'Pretentious, academic film art' ... Still from Otolith II (2007) by the Otolith Group. Photograph: The Otolith Group

The Turner prize is about finding and rewarding brilliance, and it should be able to convince us that someone on the shortlist might turn out to have a touch of genius. Two of this year's list, the Otolith Group and Dalwood, are in my opinion duds – as far from genius as it is possible to get. Which leaves two worthwhile contenders, Philipsz and de la Cruz (for my money Philipsz is a good early bet if you're after a winner, and may well capture imaginations when the exhibition opens its doors). But two decent artists out of four is not enough.